diff

A tool that compares two screenshot image files and measures how many pixels differ.

In plain words
What is it for?
Use it to compare expected and actual screens, create a visual diff image, output JSON metrics, or gate screenshot checks in continuous integration.
Why use it?
It replaces visual guesswork with a repeatable comparison and can fail a check when the difference exceeds a chosen percentage.

Command

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/cesarandreslopez/tauri-agent-tools/diff
Clone the repo
git clone --depth 1 https://github.com/cesarandreslopez/tauri-agent-tools
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 433 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00433
Opus 5 $0.00000 $0.00217
Sonnet 5 $0.00000 $0.00087
Haiku 4.5 $0.00000 $0.00043

Measured 3d ago against content hash 332838ecc1c8, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

diff scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

docs/commands/diff.md · 70 lines

What it actually says

diff

Compare two screenshots and output difference metrics.

!!! note "No Bridge Required" This command operates on local image files — no bridge or running Tauri app needed.

Usage

tauri-agent-tools diff <image1> <image2> [options]

Options

Option Description Default
<image1> First image path (required)
<image2> Second image path (required)
-o, --output <path> Write a visual diff image to this path
--threshold <percent> Fail (exit code 1) if difference exceeds this percentage
--json Output structured JSON

Examples

Basic comparison

tauri-agent-tools diff /tmp/before.png /tmp/after.png
Pixels different: 1500
Total pixels:     2073600
Difference:       0.072%

Generate a diff image

tauri-agent-tools diff /tmp/before.png /tmp/after.png -o /tmp/diff.png

Threshold gating (CI use)

# Fail if more than 1% of pixels differ
tauri-agent-tools diff /tmp/expected.png /tmp/actual.png --threshold 1
echo $?  # 0 = pass, 1 = threshold exceeded

JSON output

tauri-agent-tools diff /tmp/a.png /tmp/b.png --json
{
  "pixelsDifferent": 1500,
  "totalPixels": 2073600,
  "percentDifferent": 0.07233,
  "diffImage": null
}

Requirements

Requires ImageMagick installed on the system. Both v6 (compare, identify) and v7 (magick compare, magick identify) are supported automatically. The --threshold option requires identify to compute image dimensions.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 3d ago First seen · 70 lines · 0 tokens per session scan A 332838ecc1c8

Subscribe to this mod's changes

diff is a command published in the GitHub repository cesarandreslopez/tauri-agent-tools (22 stars, last pushed 9d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 433 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.